Gripper mechanism for material handling device



Oct. 27, 1959 F. J. SEHN ETAL GRIPPER MECHANISM FOR MATERIAL HANDLING DEVICE Filed Feb. 18, 1957 2 Sheets-Sheet 1 In: in!

0a. 27, 1959 F. J. S EHN ETAL GRIPPER MECHANISM FOR MATERIAL HANDLING DEVICE Filed Feb. 18. 1957 2 Sheets-Sheet 2 INVENTORJ rAw/vc/s J7 Ji/M/ GRIPPER MECHANISM FOR MATERIAL HANDLING DEVICE Francis J. Sehn, Detroit, and Maurice M. (Ilemons, 1Eir= minglram, Mich; said Clemons assignor to said Sehn Application February 18, 1957, Serial No. 640,714

3 Claims. (Cl. 2L9488) The present invention relates to a gripper mechanism for a material handling device and, more particularly, to a gripper mechanism for grasping a part in a press or the like duirng the operation of a part extraction mechanism.

In the extraction of parts from a press, die casing machine, or the like, the use of mechanical handling equipment has become widespread. Such equipment generally comprises a frame or arm which is movable toward and away from the press, and a jaw assembly which is actuated to engage the part prior to its extraction. Such jaw assemblies commonly utilize a freely pivotal finger which depends from the rcciprocable carriage, the carriage being actuated by a fluid pressure cylinder and the finger being closed to a gripping position by its abutment with a fixed stop on the carriage slide. The finger and carriage are provided with parts-engaging pads or points which can readily engage a projection on the part which lies in the plane of movement of the carriage. However, the heretofore utilized jaw assemblies are not adaptable for the extraction of parts in which the projection lies vertically or in any plane other than that in which the carriage reciprocates.

The present invention provides a new and improved gripper mechanism or jaw assembly for part extraction machinery generally. More specifically, this invention provides a gripping mechanism which makes possible the extraction of a part having a flange or projection which lies askew to the plane of movement of the material handling apparatus associated with the gripping mechanism.

structurally, the device of the present invention comprises a reciprocable carriage which forms a first gripping element movable in a planar path into engagement with the part and a second gripping element carried by the carriage and movable both horizontally and vertically with respect thereto. in the retracted position of the gripping mechanism, the second gripping element is angularly disposed with respect to the carriage, so that the part engaging portions thereof are vertically disposed with respect to the similar portions of the carriage. In the event the part is provided with an upstanding flange which must be grasped to remove the part, the second gripping element generally overlies the carriage. 'Ihe carriage and the second gripping element are comovable until the gripping portions thereof are disposed on opposite sides of the plane of the flange and approximately equidistant therefrom. The carriage and the sec ond gripping means are now moved relatively so that the gripping portions thereof approach the flange from opposite sides with the gripping portions finally engaging opposite portions of the flange. Actuation of the material handling mechanism associated with the gripper assembly can now extract the part from the machine.

It is, therefore, an important object of this invention to provide a new and improved gripper mechanism for a material handling device.

atent G p 2,910,321 Patented Oct, 27, 1959 Another important object is the provision of a gripper mechanism for utilization in the extraction of a part from a press or the like.

It is a further object of this invention to provide an improved gripper mechanism adapted to engage a flange angularly disposed to the direction of movement of the gripper mechanism.

Yet another important object is the provision of a material handling mechanism for removing a part from a press or the like and having a gripping mechanism including a pair of gripper elements relatively movable both longitudinally and vertically into engagement with opposing sides of a part flange or the like lying askew to the path of movementof the material handling mech- 'anism.

It is a still further object to provide a gripper mechanism having a longitudinally reciprocable carriage and a gripping element angularly disposed with respect thereto and interconnected with the carriage through cam means operative to effect abutment of the carriage and the engaging means with opposite sides of a flange disposed angularly with respect to the path of movement of the carriage.

On the drawings:

Figure 1 is a side elevational view of a material handling apparatus provided with a gripper mechanism of the present invention;

Figure 2 is a View similar to Figure 1 illustrating the apparatus in an adjusted position wherein the gripping mechanism is closed for engagement with a part;

Figure 3 is an enlarged fragmentary side elevational view, with parts broken away and in section, illustrating the gripper mechanism;

Figure 4 is a sectional view, with parts shown in elevation, taken along planes 4-4 of Figure 3; and

Figure 5 is a sectional view taken along the plane 55 of Figure 3. l

in the drawings: 1

In Figure 1, reference numeral 10 refers generally to a material handling apparatus of the type disclosed in our earlier-filed, pending applications Serial No.'555, 413 (now issued Patent No. 2,781,136, dated February 12, 1957), and No. 636,826, filed in the United States Patent Office on December 27, 1955, and January 28, 1957, respectively, and both assigned to the asignee of this invention.

Generally, the material handling apparatus 10 comprises a fixed frame element 11 carrying a longitudinally extending guide rod 12 upon which is slidably disposed a second or movable frame 13. The frames 11 and 13 are relatively telescopically movable through the actuation of a fluid pressure cylinder 14, the piston rod 15 of which carries a pinion 16 engageable with a reaction rack 17 on the frame 11 and an output rack 18 on the frame 13. Actuation of the cylinder 1 1 will effect reciprocation of the frame 13 to an extent greater than the extent of movement of the rod 15, because of the overspeed gearset 16, 17 and 18, as described in detail in the earlier of our above-identified patent applications.

The movable frame 13 carries a vertically adjustable side plate 20 upon which is disposed an upper pivot plate 21. Pivotally connected to the plate 21, as through a pivot pin 22, is a lower pivot plate 23 carrying a jaw assembly indicated generally at 25. The upper and lower pivot plates 21 and 23 are relatively pivotal about the 7 axis of the pin 22 and are normally maintained in their generally parallel relation (as illustrated in Figure 1) by a compression spring 24 interposed between the plates and an adjustable stop 26 carried by the lower plate 23 and abutting the upper plate 21.

Retraction of the piston 15 within thecylinder 14 will move the frame 13 forwardly upon the guide rod 12,

thus advancing the jaw assembly 25 toward the press or other production machine with which it is being utilized. At the forward end of the retraction stroke of the piston 15, a roller 27 carried by the lower pivot plate 23 will abut a swingable abutment arm 28 carried by the fixed frame and having a saddle block 29 disposed in the path of movement of the roller. Abutment between the roller 27 and the block 29 will cause pivotal movement of the arm 28 about its pivot axis, indicated generally at 3%), and the roller 27 will be depressed to move the plates 21 and 23 from their parallel position to the relatively tilted position of Figure 2. At the same time, the jaw assembly- 25 will be tilted'to its position illustrated in Figure 2.

Upon retraction of the movable frame 13, as upon extension of the piston rod 15, the jaw assembly will be swung vertically through the coaction of the arm 28 and the roller 27, so that a part is removed vertically from the machine. Further extension of the piston rod 15 will remove the roller 27 from the arm saddle 29, so that further movement of the frame 13 will occur with the jaw assembly tilted and the plates 21 and 23 parallel, as indicated in Figure l. This operation of the mechanism and the tilting of the jaw assembly are described in detail in the latter of our prior above-identified patent applications.

As best illustrated in Figures 1, 2 and 3, the jaw assembly comprises an upper support rod 31 which is clamped in a longitudinally and pivotally adjusted position by a clamping bracket indicated generally at 32 and carried by the pivot plate 23. This rod 31 carries at its forward end a depending bracket 33 which encompasses the forward end of the fluid pressure actuated cylinder 34. The lower end of the bracket 33 fixedly engages a guide rod 35 which projects generally longitudinally of the material handling apparatus 10 and parallel to the cylinder 34. At the forward end of the guide rod 35 an abutment block 36 is positioned, this block being adjustable longitudinally of the rod 35 through an adjusting screw 37 and having an upper, rearwardly facing, concave abutment surface 38.

Disposed upon the rod 35 in surrounding relation and adapted for sliding movement therealong is a tubular sleeve 39 which has superimposed thereon and affixed thereto a carriage indicated generally at 40. This carriage 40 comprises a pair of transversely spaced side plates 41 and 42 (Figures 4 and adapted to receive therebetween the forward end 43 of a piston rod 44 reciprocably actuatable by the cylinder 34. Side plates 41 and 42 and the end 43 of the rod 44 are secured together by a transverse locking pin 45. Intermediate the side plates and generally forwardly of the pin 45 is a generally rectangular spring saddle block 46 provided with a central slot 47 for a purpose to be hereinafter more fully described.

The carriage 40 is provided at its extreme forward end with a pair of gripping pads 48 secured by suitable means, as by nuts 49, to a transverse plate 50 welded or otherwise secured to the forward ends of the side plates 41 and 42.

A gripping element or finger 55 is generally superimposed over the carriage 40 with its rear portion, indicated at 56, being interposed between the side plates 41 and 42. A transverse cam or guide pin 57 secured to the side plates 41 and 42 and projecting through an arcuate guide or cam slot 58 in the arm cooperates with a lower transverse guide pin 59 to retain the gripper element 55 in position upon the carriage. interposed between the element 55 and the block 46 is a coiled compression spring 60, the spring extending into a slot 61 formed in the rear portion 56 of the arm 55.

The forward end 62 of the arm 55 lies substantially normal to the remainder of the arm and depends therefrom into vertically and longitudinally spaced relation to the plate 50. This end 62 of the arm 55 carries a transverse plate 63 similar to the plate 50 and provided A: with laterally spaced gripper pads 64 which are secured to the plate 63, as by nuts 65. r

The operation of the gripper mechanism would be obvious from a study of Figures 1, 2 and 3. During initial stages of actuation of the cylinder 34 to extend the rod '44, the carriage 4e and the arm 55 will be moved forward jointly. The compression spring 60 will maintain the arm 55 in its forwardmost position with the transverse pin 57 bottomed at the rear end of the slot 58. However, when the lower end 56 of the arm 55 abuts the concave surface 38 of the abutment 36, further longitudinal forward displacement of the arm 55 will be prevented, while the carriage 40 will be free to move forwardly, although impeded by the compression ot the spring 60.

Further movement of the carirage 40 will effect relative movement between the arm 55 and the carriage, such movement being controlled by contact of the cam pin 57 with the edges of the cam slot 58. As a result, the arm 55 is displaced rearwardly relative to the carriage 49 against the compression of the spring 60 and the gripping pads 64 of the arm 55 and 48 of the carriage 40 will approach one another both vertically and longitudinally. The contour of the slot 53 is such that abutment of the pin 57 with the edges of the slot will move the depending end 62 of the arm 55 both vertically and longitudinally into substantial longitudinal alignment with the corresponding end of the carriage 40. The distance between the pads 48 and 64 is such that the pads 64 and 48 are preferably disposed on opposite sides of the plane through the flange or other portion of the part to be engaged by the pads, at the time of abutment between the arm 55 and the abutment surface 38. In this manner, the part flange is approached by the pads 64 and 48 from opposite sides, while at the same time the pad 6 4 is moving downwardly into alignment with the forward end of the carriage 4d. Obviously, the exact path of movement of the pad 64 may be varied by varying the contour of the slot 58.

Once the part flange has been engaged by the pads 48 and 64, the cylinder rod 15 can be extended to retract the entire frame 13, jaw assembly 25, and the part from the press. Upon retraction of the jaw assembly cylinder rod 44, the rear end 56 of the arm 55 is removed from its contact with the abutment surface 38 and the spring 66 returns the arm 55 to its position illustrated in Figure 3 of the drawings, thus releasing the part from the pads 48 and 64. The material handling apparatus is then conditioned for another cycle.

While a preferred embodiment of my invention has been described above in detail, it will be understood that numerous modifications may be resorted to without de' parting from the scope of the following claims.

We claim:

1. In a material handling mechanism for the removal of parts from a press, a gripper mechanism for engaging a vertical flange on the part, comprising a first vertically faced gripping element longitudinally movable in a planar path into substantially normal engagement with the part flange, a second gripping element carried by said first element for initial movement therewith through a part only of the path of movement of said first element, joint movement of said elements being sufiicient to dispose said elements on the opposite sides, respectively, of the vertical plane of said flange, said second element being vertically spaced from said first element, spring means urging said elements to their vertical and longitudinally spaced separation, pin means laterally extending from one of said elements and a cam slot being formed in the other of said elements, said pin means being engageable in said cam slot, one of said elements having a pivot pin extending laterally therefrom and the other element having a longitudinal surface engageable by said pivot pin so that said arms are pivotally and longitudinally movable relative one another with said pivotal and longitudinal movement being dependent on the configuration of said cam slot, and means to move said pivot pin along said longitudinal surface against said spring means.

2. In a gripper mechanism for engaging a part flange, a guide means extending longitudinally toward the flange, a carriage movable along said guide means and having a first terminal vertically faced flange engaging element, means for actuating said carriage for movement along said guide means, a gripping finger having a second terminal flange engaging element, pivot means for pivotally connecting said finger to said carriage, said pivot means being longitudinally movable relative one of said finger and carriage, cam means for directing relative longitu-v dinal and pivotal movement of said finger flange engaging element, means on said guide means for engaging said finger as said carriage is moved along said guide means so that said cam means is operable to cause said relative movement between said finger and said carriage to first lower said finger means into gripping alignment with said carriage terminal and then bring said elements toward each other in a flange gripping relation. 7

3. A gripper mechanism for a material handling device comprising guide means, a carriage longitudinally movable along said guide means, a first vertically faced gripping element at one end of said carriage positioned for substantially normal abutting engagement with a workpiece part flange in the longitudinal path of said carriage, a member displaceably mounted on said carriage having a second gripping element, connecting means between said member and said carriage accommodating both relative pivotal and longitudinal movement therebetween,

resilient means interposed between said member and carriage urging said member to one extreme of pivotal and longitudinal movement wherein said gripping elements are both longitudinally and vertically spaced, abutment means fixed relative to said guide means engageable by said member at an intermediate position in the longitudinal travel of said carriage adapted to arrest the longitudinal movement of said member during the subsequent longitudinal movement of said carriage, said connecting means including cam means for inducing controlled pivotal movement of said member to bring said gripping elements into opposed cooperating gripping relation during said subsequent longitudinal travel of said carriage, and means for moving said carriage longitudinally along said guide means to produce initially a conjoint longitudinal movement of said carriage and member, next a continued longitudinal movement of said carriage and pivotal movement of said member, and finally a gripping longitudinal movement of said carriage.

References Cited in the file of this patent UNITED STATES PATENTS 2,275,561 Sahlin Mar. 10, 1942 2,561,704 Ladewski July 24, 1951 2,583,476 Davidson Jan. 22, 1952 1 2,677,342 Miller May 4, 1954 2,759,758 Yancey Aug. 21, 1956 2,763,229 Sahlin, Sept. 18, 1956 2,781,136 'Sehn et a1 Feb. 12, 1957 2,828,998 Sellye Apr. 1, 1958 

